China is experiencing a rapid spread of the human immunodeficiency virus (HIV) epidemic, however prevention efforts have been limited. Project 2-Behavioral Intervention-aims to reduce transmission of HIV from two core infected groups (former plasma donors (FPDs) and infecting drug users [IDUs]) to their partners. Randomized controlled trial will be conducted to examine the efficacy of a theoretically-based, sill focused intervention for HIV+ adults in order to influence the following outcomes: reducing self-reports of sexual and drug or needle transmission acts; STI incidence; disclosure to and HIV testing of partners; and health-seeking behaviors. Project 2 will build on and integrate with Project 1, the epidemiological proposal, in order to implement the interventions. Linked to the results of a cross-sectional survey implemented by Project 1 that includes voluntary HIV counseling and testing program (VCT), Project 2 will recruit two subgroups of HIV+ persons from communities previously identified as high-risk areas: 1) 25-280 FPDs in 12 villages in Shanxi Province; and 2) 300-250 IDU's from 48 villages in Yunnan Province. Villages within each site will be matched on village size and the number of HIV+ persons and HIV+ persons will be assigned by village to an enhanced intervention or a standard care condition. HIV+ adults in villages in both conditions will be provided with improved access to condoms, clean needles, free HIV testing of partners, and training of health care workers to treat HIV-related infections. In addition, HIV+ adults in the intervention condition will receive a 8-session, small group intervention based on social learning theory that address reducing transmission acts, disclosure of serostatus and testing of partners, coping with stigma and health problems, knowledge of disease progression and negotiation of health care. To maintain intervention effects, monthly boosters will be offered to provide social support with monthly workshops over 18 months. The outcomes of the interventions will be monitored at a baseline interview (providing information on the impact of VCT procedures delivered by Project 1), immediate post-intervention, 6, 12, and 18 months. Project 2 will contribute to the CIPRA by designing and providing manuals for enhanced VCT for Project 1, providing systems for tracking participants longitudinally to all projects, designing preventive interventions that can be adapted for implementation with cohorts that are HIV-. The Epidemiological Project will provide protocols for collecting biological specimens for Project 2; the Statistics Core will provide guidance on data management and analysis; the training for health care providers will be disseminated to all projects.